First is a fabulous list from Joanna Penn (and if you are indie and not followingheryet, then… well, now you know better. Go follow!). Her page includes both articles on editing and a TON of fabulous resources.

Lastly, if you’re going to go with someone outside these lists, I highly suggest you check them against these two resources:

Predators and Editors: http://pred-ed.com/pubagent.ht If the editor/agent/publisher in question has ever made a habit of bilking authors, their name should be here.

Absolute Write forums: http://www.absolutewrite.com/forums/ I can’t tell you how many times I’ve been able to find info on any number of editors, agents, and small press here. Also, if you can’t find the name you’re looking for, you can post and ASK if anyone else knows about him/her/them/it. Seriously, do it. Some awesome word-loving person will answer.

I hope you find these resources helpful. I will update this post with new links and resources when I find them. Now go forth and be eidted edited!!
Know an terrific editor? ARE you a terrific editor? Shoot me an email and I’ll add your name to this list!